What are the cut points of the Western Equine Sleep Index (WESI)-height?

Cut Points of the Waist-to-Height Ratio (WHtR) Index

The optimal cut-off point for waist-to-height ratio (WHtR) is 0.5 for most adult populations, with lower thresholds of 0.46 recommended for Asian, African, and South American populations due to their higher cardiometabolic risk at lower values.

General WHtR Cut Points for Adults

WHtR is a simple anthropometric index used to assess central obesity and cardiometabolic risk. Unlike BMI, it takes into account fat distribution, which is a critical factor in determining health risks.

Standard Cut Points:

• ≥0.5: General cut-off point indicating increased cardiometabolic risk for most adult populations 1
• ≥0.6: Substantially increased risk 2

Population-Specific Cut Points:

• European and US adults: ~0.5 3
• Asian, African, and South American adults: ~0.46 3

Ethnic Variations in WHtR Cut Points

Different ethnic groups require different WHtR thresholds due to variations in body composition and cardiometabolic risk profiles:

• South and East Asian populations: Lower cut points are needed due to higher body fat percentages and visceral adipose tissue at lower WHtR values 2
• Chinese populations: Research suggests optimal cut points may be around 0.46 3
• South African populations: Optimal values vary by ethnicity within the country, with values ranging from 0.425 to 0.505 4

Advantages of WHtR Over Other Measures

WHtR offers several advantages over other anthropometric indices:

• Height independence: Recent research indicates that traditional waist-to-height ratio may unfairly penalize shorter individuals when using fixed cut points 5
• Superior predictive ability: WHtR and waist circumference (WC) have shown greater predictive ability for cardiometabolic risk compared to waist-to-hip ratio (WHR), with area under the ROC curve values of 0.97 vs 0.79-0.84 6

Measurement Protocol

For accurate WHtR assessment:

• Measure waist circumference at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest 1
• Measure height without shoes
• Calculate ratio by dividing waist circumference by height (both in the same units)

Clinical Application

When using WHtR for clinical risk assessment:

1. Primary screening: Use the appropriate population-specific cut point (0.5 for European/US populations, 0.46 for Asian/African/South American populations)
2. Risk stratification:
   • Values below the cut point: Lower cardiometabolic risk
   • Values at or above the cut point: Increased risk requiring further assessment
   • Values ≥0.6: Substantially increased risk requiring aggressive intervention

Pediatric Considerations

For children and adolescents aged 6-18 years:

• European and US youth: ~0.5 3
• Asian, African, and South American youth: ~0.46 3

Common Pitfalls and Limitations

• Height bias: Fixed cut points may unfairly classify shorter individuals as "at risk" 5
• Ethnic variations: Using universal cut points without considering ethnicity may lead to misclassification
• Measurement inconsistency: Different waist measurement protocols can affect WHtR values and risk classification

WHtR should be used alongside other clinical assessments rather than as a standalone diagnostic tool. When elevated, it should prompt comprehensive cardiometabolic risk assessment including blood pressure, lipid profile, and glucose metabolism evaluation.